1. Field of the Invention
The invention relates to a pump element for installation in a pump bore of a hydraulic block, to a hydraulic block for a brake system of a motor vehicle, and to an installation method for a pump element.
2. Description of the Prior Art
Piston pumps received in a hydraulic block are used in hydraulic vehicle brake systems of motor vehicles and are often called return pumps. In traction control, they serve to lower or raise the brake pressure in the wheel brake cylinders selectively, to enable regulating the brake pressure in the wheel brake cylinders.
Known piston pumps have a pump element which must first be installed before it can be fixed in a pump bore of a hydraulic block. In known pump elements, the last installation step before installing the pump element in the pump bore of the hydraulic block is joining together a preassembled piston assembly, which has an inlet valve, and a preassembled outlet valve assembly. The two assemblies, mounted on separate assembly belts, are fixed to one another by means of a filter element, and the filter element radially outwardly surrounds one portion of the piston assembly and is affixed to a cylinder element of the outlet valve assembly.
In the known pump element and the installation method for installing the known pump element, it is disadvantageous that at least two assembly belts are needed in order to mount the two assemblies separately. The installation is moreover complicated because it is necessary to produce many pressure bonds, so that the assemblies that are separate from one another will form stable units that do not fall apart. For instance, in the case of the piston assembly, a pressure bond must be made between a high-pressure seal, affixed to the pump piston by means of a press fit, and an inlet valve cap.